#include<bits/stdc++.h>
#define ll long long
#define ull unsigned long long
using namespace std;

const int N = 1e6 + 10, INF = 0x3f3f3f3f;

int n;
vector<int> ans;
vector<pair<int, int>> g[N];
vector<int> s;
typedef pair<int, int > PII;

struct node {
    int l, r;
    int id;
}a[N];

bool cmp(node a, node b)
{
    return a.l < b.l;
}

priority_queue<PII, vector<PII>, greater<PII> > pq;

void solve()
{
    cin >> n;
    for (int i = 1;i <= n;i++) {
        cin >> a[i].l >> a[i].r;
        a[i].id = i;
    }
    int i = 1;
    sort(a + 1, a + n + 1, cmp);
    while (true) {
        while (i <= n && a[i].l <= pq.size()) {
            pq.push({ a[i].r,a[i].id });
            i++;
        }
        while (!pq.empty() && pq.top().first < pq.size()) {
            pq.pop();
        }
        if (pq.empty()) break;
        ans.push_back(pq.top().second);
        pq.pop();
    }
    cout << ans.size() << "\n";
        for (auto x : ans) {
            cout << x << " ";
        }
}

signed main()
{
    ios::sync_with_stdio(0);
    cin.tie(0);cout.tie(0);
// #define ONLINE_JUDGE
// #ifndef ONLINE_JUDGE
//     std::istringstream in(R"()");
//     std::cin.rdbuf(in.rdbuf());
// #endif
    int T = 1;
    //cin>>T;
    for (int i = 1;i <= T;i++) {
        solve();
    }
}